Help Me Choose: 14G AMD Memory

PowerEdge 14th-generation AMD servers are very modular by nature, and you can now choose the exact quantity and type of DIMMs for your system.

• To configure your system’s memory for optimal performance, keep these best practices in mind:

º Populate all memory channels evenly with the same rank, size, and speed of DIMMs. For situations that demand mixing DIMM sizes, all memory should be chosen based on identical rank structure, and all memory channels should be populated with an identical mix of DIMM types.
º Choose the appropriate processor to support the expected memory frequency. For example, if your workload requires a memory speed of 2666MT/s, select a processor model that supports this speed.
Choose from three different dual in-line memory module types or DIMM types that can meet your needs.

Dell is supporting two DIMM types on the 14th –generation AMD servers:
  • RDIMM: Registered DIMM – Provides for higher capacity options and advanced RAS features.
  • LRDIMM: Load Reduced DIMM – Provides maximum capacity but higher power consumption.

RDIMM, or registered memory, is the most commonly used DIMM type, and offers the best mix of frequency, capacity, and rank structure choices. It provides high signal integrity — performing parity checking to detect improper addresses or commands — and increased performance for heavy workloads.

RDIMMs (Single Rank and Dual Rank)
  • Maximum frequency of 2400 MT/s
  • Maximum frequency using 2 DIMMs per channel of 1866MT/s
  • Maximum capacity of 32GB per DIMM
  • Maximum system capacity of 1TB

LRDIMM, or load-reduced memory, uses a buffer to reduce memory loading to a single load on all DDR signals, allowing for greater density.

  • Maximum frequency of 2666MT/s
  • Maximum frequency using 2 DIMMs per channel of 2133MT/s
  • Maximum capacity of 64GB per DIMM
  • Maximum system capacity of 2TB

DIMM Speed

There is only one speed option for 14G DD4
  • 2666MT/s – DIMMS will run at 1.2 volt

DIMM Speed and Frequency

The memory offerings for Dell PowerEdge 14th-generation servers are based on the double-data rate type 4 (DDR4) which operates at 1.2 volts.

PowerEdge memory speeds by type and loading:

DIMM TypeDIMM RankingCapacityDIMM Rated Voltage, Speed14th Generation Memory
RDIMM1R8GBDDR4 (1.2V), 266624001866
RDIMM2R16GB and 32GBDDR4 (1.2V), 266624001866
LRDIMM4R64GBDDR4 (1.2V), 266626662666

DIMM Comparison Table

The table below lists the comparison between different DIMM types.

DIMM Comparison

Registered/BufferedAddress onlyAddress and data
Frequency/Speed2666 MT/s2666 MT/s
Ranks Supported1 or 24
Capacity per DIMM8GB, 16GB and 32GB64GB
Maximum DIMM per Channel22
Dynamic RAM (DRAM) Technologyx4 and x8x4
Temperature SensorYesYes
Error-Correction Code (ECC)YesYes
Single Device Data Correction (SDDC) – Only supported on x4 DIMMsYesYes
Address ParityYesYes